How narrow can a slip be and be OK?

[SPC]

One of the few options in my area is 40' slip. They measure at least 18' wide. Is that just too narrow for a 16' wide 32?

[Page 83]

Floating docks don't need as much lattitude in dock lines, and can be narrower. Fixed docks mean your dock lines have to have enough slack to accomodate tidal variation., and may not keep her from hitting the lee pilings.
When you add the size of fenders you have, you will experience some slip shrinkage.
Check out the prevailing winds and the inevitable "Welcome Home" gusts.
I have found the difficulty in threading a wide boat into a narrow slip is inversely proportional to the number of shoreside observers and rigourously avoid docks at restaurants I intend to eat at.
Don't get bit by the "catamarans are easier to manuever 'cuz they got two engines" myth. Mother nature has a nautical division, headed by a Mister Murphy. Unless you have bow and stern thrusters, some situations lead many experienced cat sailors to anchor out for a while; at least till the restaurant closes!

[chicagocat]

As Sandy implied, it depends on a lot of things, tides in particular. Here in Chicago, I'd have no hesitation parking in a slip with 1 foot on each side. In, say, Miami Beach Marina, where the current is at times 6 knots with a four foot tide, no way.

[mikeandrebecca]

The slip where we kept our 32 was 18' wide. We got pretty good at backing her in.

[Phenix-former-owner]

New Buffalo, MI has slips that are 40 ft long and 17 ft wide from dock to center-post. Phenix being 16" can get in there and once she's in, there really isn't an issue because she is past the center post so won't be banging against it. But getting in and out is really not something I would want to be doing every day.

My slip in Chicago is 33 feet wide, one side is the floating dock and the other side is a concrete wall.

[thinwater]

I'm in an 18' slip and it's fine (PDQ32). Though I could fit it into less, it's nice to have some room for storms.

It may help if you run a rope from the dolphins to the dock as a hand line on both sides, particularly if you single hand.

[maxicrom]

We have a PDQ 36 and our beam is about 18' 3" - we had a slip for a while on a floating dock that was 18' 7" wide - don't ask me how but we always made it in. Only issue was that there was really no room for fenders. We went with the flat foam style and hung them on the cleats. If there was any weather we would either grab and end tie or drop the hook in the channel until the weather passed. We had that slip for about a year.